1. Field of the Invention
The present invention is directed to a portable device for mixing materials and for dispensing the mixed materials under pressure through a nozzle.
2. The Prior Art
In many instances, it is desirable to dispense a mixture of two materials which are preferably stored separately. An example of known devices are multiple spray heads which are connected to separate supplies of materials and direct the sprays to mix the materials as they are being projected onto a surface. An example of this type of device is disclosed in U.S. Pat. No. 3,033,472. It has also been proposed to provide various devices which mix two separate materials prior to being discharged through a single nozzle. An example of this type of a device is disclosed in U.S. Pat. No. 3,478,963.
In the dispensing of a mixture of two or more materials, it is often desirable to ensure that the material is well mixed by using a homogeneous device which is disclosed in U.S. Pat. No. 2,817,500 or by rotating a stirring element in the path of the flow. Different examples of rotating stirring elements are disclosed in U.S. Pat. Nos. 2,798,698, 3,181,838 and 3,181,839.
With the introduction of epoxy adhesives in which two materials are mixed to cause a chemical reaction to develop the adhesive material, various problems of dispensing the two materials in the proper proportion have existed. One solution is a double barrel dispensing device containing two cylinders of the two materials which deposit the two materials together on a surface as it is being dispensed. An example of this type of device is disclosed in U.S. Pat. No. 3,311,265. While the device of the last-mentioned patent will ensure the proper proportions, it may not provide a thorough mixing of the two materials. It has been suggested to utilize a mixing chamber having a rotating mixing element which mixes the two materials prior to their discharge through a nozzle. An example of this device is disclosed in U.S. Pat. No. 2,788,337.
When using an epoxy resin either alone or with a filler material to either repair cracks or fill holes, the material that is being dispensed must be dispensed under a large pressure so that it will extrude or flow along the surfaces of the cracks or into the hole as it is discharged from the nozzle. Therefore, not only must the two materials which combine to form the epoxy resin be correctly mixed in the correct proportion, high pressures are required to obtain the flow from the nozzle with sufficient force to force the mixture into all of the cracks and crevices being filled. This high pressure in the mixing chamber causes problems with extruding or flowing of the material around the movable parts such as the rotating shaft. This undesirable flow of the mixture will set up or harden and prevent the proper operation of the device.